Condoleezza Rice began her tour of Europe yesterday with a rare public admission that the US had made "mistakes" in the war on terror.

Speaking after a meeting with Angela Merkel, the German chancellor, Ms Rice again insisted that the US did not "condone" torture. "It is against US law," she said. But she appeared to concede for the first time that the Bush administration's uncompromising policy of "rendition" against terrorist suspects had sometimes gone wrong.

"We recognise that any policy will sometimes result in errors," the US secretary of state said. She added: "When this happens we will do everything we can to rectify it."

Her comments in Berlin came at the start of her five-day tour, which takes in Romania, Ukraine and Brussels. The visit has been accompanied by a wave of criticism from across Europe over the CIA's practice of transferring terrorist suspects to third countries for interrogation.

There were also new and embarrassing revelations yesterday that the CIA had closed down its secret jails in eastern Europe after their existence was revealed early last month by the Washington Post. According to ABC, citing CIA officials, the prisons believed to be in Poland and Romania were shut last month.

The 11 al-Qaida suspects held there were flown to north Africa before Ms Rice's trip, the network said. Ms Rice's unusual concession to US critics appears to be an attempt to deflect outrage in Germany over the case of Khalid Masri - a German national mistakenly kidnapped by the CIA in December 2003.

Standing next to Ms Rice, Ms Merkel yesterday said that the US had "accepted" it had "erroneously taken" Mr Masri, who spent five months in a freezing Afghan jail after the CIA grabbed him in Macedonia.

The affair is also bad news for Germany's former government under Gerhard Schröder. It apparently knew about the CIA blunder but agreed to US requests to say nothing about it. A special Germany parliamentary commission would now investigate, Ms Merkel said.

The American Civil Liberties Union, meanwhile, yesterday announced that it was suing the CIA and its director at the time George Tenet over his case. Mr Masri had been due to address a press conference - but was apparently unable to attend after US officials refused him permission to enter the country.

Ms Rice declined to comment directly. But asked if she could "guarantee" that the CIA would not snatch anyone else, she said: "Any policy will sometimes have mistakes. It is our promise to our partners that, should that be the case, we will rectify those mistakes."

However, Ms Rice said she had no regrets about the methods used by the CIA, insisting that American intelligence-gathering operations had "saved European lives". "We have an obligation to defend our people. We will use every lawful means to do it," she declared, arguing that it was necessary to "get the perpetrators" before they committed "mass murder". She also pointed out that Europe had been the site of several terrorist outrages, citing Madrid and London.

But it seems scrutiny of the CIA's activities in Europe is unlikely to dwindle. There were yesterday fresh claims in Italy that the CIA had deliberately deceived the authorities there over the whereabouts of a radical Islamic cleric whom the agency had in fact kidnapped.

According to the Washington Post, the CIA seized Hassan Mustafa Osama Nasr, an Egyptian refugee known as Abu Omar, from a street in Milan. The agency then told Italian anti-terrorism police that they had information that he had fled to the Balkans - a piece of disinformation. The strategy worked for more than a year, until the Italians discovered that the CIA had whisked Mr Nasr off to Egypt, where he was allegedly interrogated and tortured, the Washington Post reported.

Despite the row over the CIA, Ms Rice enjoyed a soft landing in Germany. Her Berlin visit marks the start of a new relationship between the countries following the row under Mr Schröder over Iraq.

Ms Merkel, a pro-atlanticist who took over as chancellor last month, yesterday described her meeting with Ms Rice as "important", and said it signalled a "good start" for future German-US relations. She deliberately refrained from criticising the US but said Germany took its international obligations on human rights seriously.

She had also raised the issue of CIA "overflights" following revelations that the CIA had flown to Germany 437 times.

Ms Rice later arrived in Romania, where she signed a defence cooperation pact. The pact related to an airbase near the Black Sea identified by Human Rights Watch as a site for a clandestine prison. Romania has denied hosting CIA jails. Ms Rice refused to say which countries were involved with the prisons. "Were I to confirm or deny, say yes or say no then I would be compromising intelligence information, and I'm not going to do that," she said yesterday.